I would like to highlight three non-protein amino acids; Taurine, L-Carnitine and Creatine. These amino acids are not available from direct plant sources. (Direct sources are; meat, fish, milk and eggs.) Though they should be part of a daily vegan diet, they are easily forgotten due to a lack of information.
The only small article I found on the web, from the vegan websites I know, is at VeganHealth. They are linking to an article related to Carnitine deficiency. I would like to start with an introduction about Taurine.                                                                                                                                                  


 







Omnivores (Humans) don't make enough taurine in their own body. Unlike herbivores, they need external sources... Originally Taurine used to be derived from the bulls testicles. Bulls make and store a lot of taurine in it."Red Bull" a famous taurinedrink uses a synthetic source though.


Why so little information?

Probably because at first there shouldn't be a problem for most vegans:
Adults can produce taurine by a combination of cysteine with the help of pyridoxine = B6, methionine and vitamin C.
Cysteine is found in red peppers, garlic, onions, broccoli, Brussels sprouts, oats, granola and wheat germs. B6 in whole grain products, vegetables, and nuts. High levels of methionine can be found in sesame seeds, Brazil nuts and some other plant seeds. Significant amounts can be found in spinach, potatoes, and boiled corn.

Since these sources are normally without any problem part of a vegan diet, the following groups either do not produce taurine by themselves and/or need additional amounts because they do not produce enough to their needs:

    * Premature infants.
    * Children.
    * Pregnant or breast-feeding women who are vegan/vegetarian.

As an adult if;

    * Your body does not make enough due to inadequate intake of calories, protein or nutritional dietary. (Especially when cysteine, methionine or B6 is deficient).
    * You are deficient in the enzyme needed to make taurine. Found in (natural) sources such as brewer's yeast, eggs, milk, fish and red meat.
    * You have candida. Which causes you lose taurine through you urine.


Importance of Taurine

Taurine, an amino acid (in short; building blocks for protein), is not part of our muscle protein yet is important in metabolism, especially in the brain. It maintains cell membranes, regulates heart beats and protects the heart from calcium overload.


Especially mothers or future mothers should know that taurine is the highest concentrated amino acid in the brain of the fetus and newborn. The fetus must obtain it through the placenta, newborns through breast milk or infant formula fortified with taurine; however, the amount in these substances is considered inadequate for infants.

There is no Recommended Daily Allowance (yet) for taurine, to give you an idea from what I have read in several sources*: Infants and small children need about 27-58mg per kilogram of bodyweight.

Parents or future parents should be aware of the importance of taurine since (moderate) deficiencies may lead to; slowed growth and low levels of essentials proteins in blood.
Eventually severe deficiencies may lead to; apathy, depigmentation of hair, edema, lethargy, liver damage, loss of muscle and fat, skin lesions and weakness.

(Other non-proved reported symptoms; anxiety, depression, hypertension, hypothyroidism, gout, infertility, obesity, kidney failure and autism).


Synthetic options for taurine


Solgar 500mg vegicaps
Via Veganfitness we found the cheaper option for sale at myprotein.co.uk.

Always discuss with you doctor, before just taking these supplements, about your own specific needs.

There are no known toxicity levels for taurine; however, excessive levels may cause diarrhea and peptic ulcers.

*References;
bodyecology
MDadvice
supplementnews
ChiroFind
Wikipedia